Retractable light indicator at substations



1949 R. M. WORTMAN ET AL 2,477,918

RETRACTABLE LIGHT INDICATOR AT SUBSTATIONS Filed Aug. 20, 1945 2 Sheets-Sheet 1 ATTORNEY Aug. 2, 1949. k. M. WORTMAN ET AL 2,477,918 RETRACTABLE LIGHT INDICATOR AT SUBSTATIONS Filed Aug. 20, 1945 2 Sheets-Sheet 2 INVENTORS flamdoM/Wlriman ATTORNEY Patented Aug. 2, 1949 RETRACTABLE LIGHT INDICATOR AT SUBSTATIONS Randolph Milton Wortman, Alexandria, Va., and Ralph E. Webster, Washington, D. C.

7 Application August 20, 1945, Serial No. 611,524

2 Claims.

This invention relates to indicators for telephone circuits, and particularly to visual indicators for telephone sets.

The standard equipment of office telephones consists in providing each telephone with a bell which is rung in response to energization of the individual ringing circuit of that telephone. After ringing has ceased, there is no record of a call having come in. Where a plurality of telephones are juxtaposed in the same ofiice, it is diificult to ascertain which telephone is being called, and prior art attempts to distinguish one from the other by diiferent types of telephone bells have not been entirelysatisfactory. They are, for example, ineffective when the person being called has defective hearing, or when the telephones are placed in locations where there is much extraneous noise. Special bell sounds also have to be learned by new personnel.

The present invention is designed to overcome prior art handicaps by providing each individual telephone with a visual indicator which is operative in the presence of noise and leaves a record that a call has come in. It may consist either of a projectable member which is released when the ringing circuit of the telephone is energized, or of a projectable member used in conjunction with a flashing light.

The objects of the present invention are, therefore, to eliminate the diificulty and confusion incident to the juxtaposition of several phones at the same location by substituting visual for audible signals, by providing means for indicating that a call has come in, in the absence of the attendant, and providing a resetting device associated with the signal so that after a call has been received the mechanism can be reset for a subsequent call. Numerous other advantages of the invention will appear from the following specification when it is read in connection with the accompanying drawings in which Figure 1 is a plan view of a known type of telephone set having a device of the present invention attached thereto;

Figure 2 is a side view of the telephone set shown in Figure 1, with parts broken away to show the interior construction;

Figure 3 is a bottom view of a portion of a lighting device shown in Figure 1;

Figure 4 is a sectional view onthe line 4-4 of Figure 3;

Figure 5 is a detailed sectional. view of the projectable device shown in Figures 1 and 2;

Figure 6 is a sectional view on line 6-5 of Figure 5; y

Figure 7 is a partial elevation showing a modification of the invention in which the light is combined with the projectable device;

Fi ure 8 is a detailed sectional view of the combined device shown in Figure '7;

Figure 9 is a detailed view of a latch device used in connection with the invention; and

Figure 10 is a simple circuit diagram showing how the present invention is applied to the ringing circuit of a telephone to be equipped.

Referring now to Figures 1 and 2 of the drawing, the reference character H designates generally atelephone set of conventional type including dialing mechanism and the usual hand set transmitter and receiver. This type of telephone set is disclosed because it is the most common type now in use, but it is understood that this invention is not limited to use with this particular type of set, but has general application to any telephone which employs a ringing circuit. While it is preferred that the indicator be housed within the frame of the set, even this is not essential.

In telephone sets of the type indicated it is usual to dispose the ringing and dialing mechanism within the base. According to the present invention it is proposed to add to this mechanism a very simple indicating device so as to give a visual indication that the ringing circuit has been energized. Consequently, if the attendant is absent when the call is received, there will be an indication that the call has come in. In the presence of the attendant there will be a visual indication manifested either by the projection of a projectable member alone or in combination with the flashing of a light in synchronism with the pulses of ringing current. The two indicators may be combined or they may be disposed separately. While it is preferred in the practice of the invention to combine them in order to simplify and unify the device, both forms will be described in the present application in order to indicate the broad scope of the invention and the flexibility which it has in service.

In Figure 1 there is disclosed adjacent the forward portion of the telephone base an impact operated indicator including a projectable member or plunger 22 which is adapted by its position to indicate whether or not the telephone ringing circuit has been energized. In other words, when the plunger is in retracted position as shown in Figure 2, it is held latched in that position, but when the ringing circuit is energized, it will be projected by a mechanism shortly to be described. Consequently, the plunger memher constitutes an indicator and after being projected must be manually restored. It may be used alone or in combination with a light which flashes in response to the pulses of the ringing current. The light designated I4 is disposed behind a colored jewel designated l5 in Figure 1.

In practice the light I will be a low voltage lamp such as a neon lamp which draws a negligible amount of current.

The indicating device will now be described in detail and will be best understood by reference to Figures 5 and 6 of the drawing. In Figure 5 the tubular shell is designated i5 and includes a threaded portion I! of reduced diameter which extends through an opening in the base it? of the telephone. It is clamped in position by a nut IS. The member l6 includes a small bore 2| through which passes the plunger member 22 containing a recess in its lower portion to accommodate a projecting spring 23 which sur-- rounds a stud 25 carried centrally of a cap 25 threaded over the open end of the member I5. Disposed around the periphery of the member is is a latch, the details of which are shown in Figure 5. It comprises a single member bent to form two ring-like portions 26 and 2? connected by a strap 28. The small ring-like portion 25 is clamped between the shoulder on the member to and a nut i2. The assembly is secured to the casing when the nut 29 is tightened. The large ring-like portion 2'! embraces the member IE5 loosely and carries a latch finger 23 adapted to pass through an opening 3| in the member l5 and to engage the forward portion of a flange 32 formed on the lower end of the plunger 22. The spring 23 therefore biases the plunger outwardly toward the dotted line position shown in Figure 5, but is prevented from doing so, so long as the latch finger '29 engages :le flange 32 as shown in that figure.

As so far described, this device includes means for manually depressing the plunger 22 to the position shown in Figure 5 where it is held. Inasmuch as it is intended to indicate energization of the ringing circuit of the telephone, it includes means for releasin the latch and projecting the plunger whenever the ringing circuit is energized. Consequently, the strap 28 carries an angular member which is attached to it as shown in Figure 5 and includes a flat striking surface 35 adapted to cooperate with one face of the clapper 35 of the telephone bell. It will be clear that when the clapper moves in a horizontal plane, it will strike the face 34 moving the latch 29 outwardly from its slot and causing the spring 23 to project the plunger when the latch is here disengaged from the upper face of the flange 32.

The complete assembly is shown in detail in Figure 2 where it is apparent that one of the usual telephone bells is removed and is replaced by the device l2. Although here one of the telephone bells 35 is shown still in position, it may also be omitted if desired. In practice the lamp E4 is included in circuit with the ringing mechanism so that when ringing current passes through that circuit, the clapper will move and cause member 22 to be projected, and at the same time the light I4 will flash in synchronism with the pulses of the ringing current.

As shown in Figures 1, 3 and 4, the colored jewel I5 is held in position by a locking ring 36 carried in recesses i3 in the jewel and snapped in place as shown in Figure 3. The lamp M is disposed directly behind it so that there are two means of visual indication here shown; namely, the position of the retractable plunger 22, and the light flashing behind the jewel 5.

The operation of this circuit will be understood from reference to Figure 10 where the ringing circuit, including the line conductors 31 and 38, is indicated diagrammatically as feeding cur rent to the electromagnet 39 acting through armature 4| to actuate the clapper 42. The usual biasing spring 43 is provided, and it will be clear that when pulsating ringing current is supplied to these magnets the clapper 42 will vibrate in conventional manner between the bell 44 and the striking surface 34 on the latch release device. Since the lamp I4 is included in the ringing circuit, it will flash in synchronism with the pulses of the ringing current.

The apparatus just described shows one form in which the invention may be embodied, but in practice it is preferred to combine the light indicator and the visual indicator in a single unit in order to simplify the installation and to make it necessary to provide but a single perforation in the casing of the telephone base. The preferred form of the invention is shown in Figures '7 and 8.

Referring now to Figure 7, it will be seen that the telephone base includes the projectable member just described which may be placed in position by punching a. single .hole in the casing l8 of the telephone. Disposed directly beneath the projectable member is the light it in a position to project light axially through the projectable member. In this form of the invention the projectable member is made of a transparent plastic which has the property of collimating the rays of light and projecting them longitudinally and in parallel relation. Consequently, it is preferred to make the plunger designated 5| of transparent plastic, such as Lucite, polystyrene, of the like. structurally the device shown in Figure 8 corresponds closely to that in Figure 5 except that the parts in Figure 8 are made of transparent plastic so far as possible, and the lamp is disposed directly beneath and in longitudinal alignment with the retractable plunger.

Referring now to Figure 8, the casing I5 is constructed exactly as it appears in Figure 5, and may be of metal. In this instance, however, the plunger 5| is made of the transparent plastic and the cap 52 including the stud 53 correspond structurally to the cap and the stud 2! shown in Figure 5, except that they are here made in one piece from transparent plastic. In this form of the invention the striking surface associated with the clapper forms an integral part of the strap associated with the latch 29. In other words, in this form of the invention the strap connecting the two rings 54 and 55 includes a fiat striking surface 56 arranged in parallel relation to the cooperating face of the clapper 35.

The operation of the arrangement shown in Figure 8 corresponds closely to that which has previously been described, and the circuit arrangements are the same. The result is, therefore, that whenever the ringing circuit is energized with the plunger 5| in the position shown in Figure 8, the lamp M will flash and will project its rays longitudinally through the plunger 5| to give visual indication that the ringing circuit is energized. At the same time the movement of the clapper 35 will cause it to engage the striking face releasing the latch 29 and causing the spring 23 to project the plunger 5| to its extended position. Consequently, as

shown in Figure '7, the attendant will have two ways of ascertaining that a call is being received. One is by observation of the member 5| which will glow due to the flashes of light which are projected through it, and the other that the member 5| will be projected to outstanding position where it is visible as contrasted with its retracted position of substantial invisibility. The light will, of course, flash only so long as the ringing circuit is energized, whereas the member 5| will remain projected until reset.

The lamp, when included in the combination, is operative at all times, regardless of the position of the projectable member. While the receipt of a call will release the projectable member from its retracted position, subsequent calls received before the member is reset will have no effect other than to flash the light. For this reason it is preferred to use the light and the projectable member together, so the light is always effective to give an indication even when the projectable member has not been reset after a prior call.

It will be clear from the past description that this invention is capable of being embodied in several difierent ways but that basically it consists in a simple attachment which may overcome many of the difilculties which are incident to the use of a plurality of telephones at a single location. The use of this invention will not only decrease the confusion incident to such arrangement, but will make the scheme operative for strange personnel as well as for people with defective hearing or working under conditions where the noise level makes it highly impossible to distinguish between tones of different telephone bells.

It is also to be pointed out that this invention may constitutea simple integral unit which may be placed in position in a standard telephone set without any alteration of that set other than the removal of one of the telephone bells, the use of one or two screws for dual purpose, and the punching of a small opening in the casing of the telephone set base. detract adversely from the appearance of the telephone set, and when made of colored plastic may actually improve the appearance. It will not alter the standard circuit in any way, because it is merely necessary to include the small glow The device does not lamp M in the ringing circuit. It does not take sufiicient current to alter the ringing characteristics of the set.

Although only two ,forms of the invention have been described specifically, it will be obvious that numerous embodiments are possible within the scope of the invention, and it is contemplated that they are to be embraced within the appended claims.

Having thus described our invention, what is claimed is:

1. The combination with a telephone set having a ringing circuit, of a signal comprising a transparent member movable between retracted and projected positions, an electric lamp disposed to project light through said member, means for latching said member in retracted position, and means controlled by energization of said ringing circuit for causing said member to be moved to projected position and said lamp to project a series of light flashes through said member in synchronism with the pulses of ringing current.

2. The combination witha telephone set having a ringing circuit of a transparent member carried by said set and capable of occupying either of two positions; an electric lamp connected to said ringing circuit and disposed to illuminate said member, means for latching said member in one position where it is held when said ringing circuit is de-energized, and means actuated by energization of said ringing circuit for releasing said member for movement to the other of said positions with concurrent flashing of said light.

' RANDOLPH MILTON WORTMAN.

RALPH E. WEBSTER.

REFERENCES CITED The following references are of record in the flle of this patent:

UNITED STATES PATENTS Altoonian Apr. 16, 

